Effetti a lungo termine di una dieta a basso versus una dieta a moderato contenuto proteico sulla progressione della insufficienza renale cronica

Background: Whether low protein diet (LPD) regimens as opposed to moderate protein restrictions (MPR) improve long-term survival of Chronic Kidney Disease (CKD) patients or induce protein caloric malnutrition (PCM) remains unknown. Study Design: Intention-to-treat analysis of follow-up data from a randomized controlled trial on the metabolic effects of LPD v MPR (0.55 v 0.80 g/kg/day). Setting & Participants: 423 CKD (Stage 4-5) patients were randomized between January 1999 and January 2003, and followed until December 2006 or death. Outcomes: PCM, dialysis, death or composite outcome of dialysis and death. Measurements: Cox regression was used to model time to dialysis initiation and death as a function of protein regimen while taking into account biochemical and clinical data. Results: The average protein intakes were 0.73±0.04 g/kg/day (Gr-0.55) and 0.9±0.06 g/kg/day (Gr-0.80). After an average follow-up of 32 months (median 30 months, 1st and 3rd quartile: 21 to 39) only three patients met the criteria for PCM. The cumulative incidence of death or dialysis start were unaffected by the diet regimen, with 113 patients reaching the composite outcome: 56 (26%) patients in the Gr-0.55 and 57 (27%) patients in the Gr-0.80. Only 11% of participants died during the study, with 66% and 64% remaining dialysis and death free in the Gr-0.55 and Gr-0.80 respectively. Limitations: Secondary analysis of trial data. Conclusions: Our study shows that (1) the prescription of a low protein diet does not lead to protein wasting; (2) most patients, regularly followed in CKD clinics, remain acceptably compliant to the prescribed dietary protein intake restrictions; and (3) low protein diet does not seem to impact patient outcomes.